Mode oe supplying steam to promote combustion in furnaces of steam



UNITED STATES PATENT OFFICE.

JNO. B. PETITVAL, or CHARLESTON, sOU'rH CAROLINA.

MODE 0F SUPPLYING STEAM TO PROMOTIE CMBUSTIO IN FURNACES OF STEAM-BOILERS, &C.

Specica'ton of Letters Patent No. 1,250, dated July 1'?, 1839.

To all whom it may concern Be it known that I, JOHN B. PETITVAL, ofCharleston, in the district of Charleston and State of South Carolina,civil engineer, have invented a new and improved mode of supplying steamto aid in the combustion of fuel in the furnaces of steam-engines of allkinds and which may also be applied to furl naces for other purposes;and I do hereby declare that the following is a full and eXactdescription thereof.

Under the fire, or grate, bars of the furnace to which my improvement isto be applied, I aflix or suspend the apparatus which I have devised forthe purpose of giving a supply of steam to the fire; this apparatusbeing applied without its being necessary to make any alteration in theordinary fire bars, or in any other part, of the furnace. In its form,my apparatus bears a resemblance to the grate of the furnace, beingcomposed of bars which may be so arranged, as, when in place, to besituated immediately under those of the furnace, and thus present noobstruction to the falling of the ashes from the lire; these bars arehollow, having each a perforation, or channel, for the passage of steamfrom end to end; from these channels there are numerous small lateralpassages for the escape of steam under the fire bars of the furnace.These perforated bars are connected at each end by cross bars, and theirperforations open into a channel, or tube, formed in these cross bars,for the purpose of establishing a free passage for steam throughout thewhole system.

I usually construct this apparatus of castiron, the upper and lowerportions of the perforated bars being cast separately, and in such formas that when the two portions are put together, they will have withinthem the necessary channels and apertures for the passage of steam.

The apparatus thus constructed may be said, therefore, to consist of twoparts, or frames, separable from each other horizontally, and, when dulyjoined together, constituting the apparatus in question.

In the accompanying drawing, Figure 1, represents the upper surface ofthe under division of the apparatus, which is shown as cast in oneentire piece. a, a, a, are channels, or grooves, formed along the barsZ2, 6,' and c, c, c, are lateral openings to allow of the escape ofsteam from the channels when the apparatus is in action; el, cl, are theends of the frame, and e, c, c, e, flanches to aid 1n the connecting ofthe upper and lower portions with each other.

F ig. 2, represents the under surface of the lower division abovedescribed; like parts, where they are seen in this, or the otherfigures, being designated by the same letters of reference as in Fig. l.The part j, f, of the ends d, d, are curved, as within them are formedthe tubes by which the respective channels in the bars I), `7), b, areconnected with each other. This is shown distinctly in Fig. 3, in whicho, Z2, is a longitudinal section of one of the bars, and g, g, theconnecting tubes formed in the ends CZ, d; the bulge, or convexity, onthe lower sides of these ends being seen at f, f.

Fig. 4t, shows a segment of the upper side of the upper frame havingbars o', Z2', connected together b y the end pieces d', cl. Fig. 5, is asegment of the under side of said frame, in which it will be seen thatthe bars b, b, are triangular in their cross section. The angular edgesalong the under sides of these bars enter into the grooves, or channels,formed along the upper surfaces of the bars ofthe lower frame, to whichthey are to be nicely fitted, leaving a free passage for steam along thechannels, below the angular edges. The two frames are to be unitedtogether by screw bolts passing through holes in the side and end bars,and through those in the flanches c, c, c. Should it be found necessaryfrom the springing of any of the bars, clips may be applied to them inparts intermediate between the flanches.

W'hen the apparatus has been thus prepared, and adapted, in size andform, to the particular furnace to which it is to be applied, it is tobe placed in the ash pit, immediately below the fire bars. It may besuspended from these bars by links, or it may rest on ledges prepared tosust-ain it. Then in use, steam is to be admitted into the tubularopening in the front cross bar cZ, Fig, 3, through a steam tube 7L,which may be supplied from the waste steam of a steam engine, or in anyother convenient way. In Fig. 2, z', is an opening for the reception ofthe tube It. To this apparat-us, when in place, I give an inclinationfrom front to back, say of one inch to a foot, in Order that any waterwhich may collect from the condensation of steam may flow from the frontinto the tube g, in the rear cross bar. From this tube a discharge pipej, j, conducts any accumulated water, and discharges it in front of theash pit; this discharge pipe must, of course, have an inclinationdownward from the back toward the front of the ash pit, sutlicient todispose the water to run along it; stop cocks are used to regulate thisand the supply tube. y

Although I have spoken of using a singley set of bars only, throughwhich steam mayv be emitted, there may be two, or more, one above theother, should it be found advantageous. And, although I have described aparticular manner of constructing my perforated bars of cast-iron, I donot intend to limit myself to the precise mode of construction hereingiven, or to the use of cast-iron. Instead of casting two distinctframes, and combining them together in t-he manner described, a singleframe only may be cast, with channels, or grooves, and upon these may bebolted, or otherwise affixed, bars cast in the form of a triangularprism, or in any other convenient shape, so as to form the tubularopenings along the bars of the frame. The frame itself, also, may beinverted, so as to make what I have called the Linder division the upperone; and this, indeed, may be preferred, as protecting the lateralopenings the more perfectly from dust. I have said that I usuallyconstruct this apparatus of cast-iron; but it may be made in part, oraltogether, of Wrought-iron, in which case the drawn iron gas tubes maybe substituted for the cast-iron bars, holes boing drilled in them,laterally, for the emission of steam; the end pipes may, also, in thiscase, be of wrought-iron, or they may be cast, the wrought-iron pipes,if thought l proper, being laid in the molds so as to be embraced by thecast metal.

Having thus fully described the construction of, and the mode of using,my apparatus for supplying steam to aid combustion in the lires offurnaces, what I claim as my invention, and desire to secure by LettersPatent, is

1. The making and using of a grate-formed apparatus, consisting ofhollow bars furnished with lateral openings for the emission of steam,said apparatus to be placed below the ordinary re bars in the ash-pit ofa furnace, for the purpose described, and its general construction andoperation being such as is herein set forth.

2. I also claim the particular manner of constructing said apparatus, bycasting it in two separate portions, which when placed one upon theother, and properly confined together, will leavethe necessary channelsfor the conveyance and emission of steam, substantially as herein fullymade known.

I am aware that the fire bars of furnaces have themselves been madehollow for the passage of water through them,and I believe, also, thatit has been practised, or proposed, to make lateral openings in suchbars for the escape of a portion of water, or of steam, therefrom; butit will be seen that my invention is specifically dierent from this, asin all cases, whatever may be the particular mode of constructing, orputting together, my apparatus, it is to be used independently of, andseparate from, the ordinary tire bars.

J. B. PETITVAL.

Witnesses JAMES TREAT, AUG. W. RADCLIFF.

